Conventional hard disk drives have a media formed on a rotatable disk for storing information. The information is both servo information stored in servo sectors on the disk media and data stored in data areas between the servo sectors. A read/write head flies over the rotating disk in order to read information from both the servo sectors and the data areas and write information to the data areas. The servo information is used by the read/write head control system to determine the location of the read/write head relative to the servo sectors. However, when the read/write head is flying over a data area, there is no servo information available for servo feedback and control.
In a dedicated servo system, this issue is addressed by having a magnetic dedicated servo layer in addition to the usual magnetic data layer in the disk media. This may be referred to as a buried servo layer. With the additional dedicated servo layer, much or all of the servo information is placed into the buried servo layer, leaving more space in the data layer for data areas.
In conventional hard disk drives, the head either reads or writes, but cannot perform both operations simultaneously. However, in the dedicated servo implementation, in addition to increased data space, the dedicated servo layer allows reading location information and monitoring position signals from the servo layer even when the recording head is performing a data write operation.
Yet, during a write operation, the write signal is necessarily coupled to the read signal, interfering with reading the servo signal while writing to data areas. The interference of the write signal is likely much stronger than the read signal and therefore poses a challenge in the recovery of useful information from the servo signal while writing to the data layer.
Thus, what is needed is a method and apparatus for reducing or eliminating interference between the write signal and the read signal in order to advantageously implement the dedicated servo layer for a robust read while write operation. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure.